Healthbeat Report: The Secret Fifth Flavor

Most of us know about salty, sweet, bitter and sour. But there's also a flavor many of us have never heard of but experience every day. It's called umami.

The public is probably going to be hearing more about it as cooks, food product developers and nutritionists realize its potential.

Foods naturally rich in umami are thought to be very satisfying to the stomach and the brain. And researchers are just starting to understand how the umami taste may help fight the battle of the bulge.

Many of us know when we are craving something salty or sweet. But what about those foods with a distinctive taste, so delicious, savory or satisfying we think about them even after the meal is over; pizza with Romano cheese, roasted meat or sautéed mushrooms for example.

Chances are those foods you long for but can't quite explain why are rich with what the culinary and scientific experts are calling the fifth sense: umami.

"Your fifth taste sense. I didn't know I had five taste senses," said Judy Vlack .

Most people don't but many chefs have been incorporating it into their dishes for years.

Umami comes from a Japanese word meaning delicious or savory. And researchers now know our taste buds can detect umami flavor

Dietitian Jacqueline Marcus has been studying umami for years. She says umami can be found in foods with amino acids, the building blocks of protein, like aged beef, parmesan cheese, and shiitake mushrooms.

The amino acid that is mostly responsible for the umami taste is called glutamate. And scientist's say there are also a few others.

So why should we be interested in knowing more about this fifth taste?

Dr. Hirsch studies the relationship between smell and taste and how it influences what we eat. He says umami foods are not just satisfying to the palate but they are thought to make you feel full faster. .

"If you arrange your diet not just in calories but how insatiating the food is it will be much more effective in people losing weight," said Dr. Hirsch. "It's because of that turn off mechanism that umami brings to your body. So you eat something and your body quickly says, 'done we've eaten enough.'"

Here's a quick list:

cheese

mushrooms

tree nuts

tomatoes

black olives

soy sauce

Other examples include smoked or cured meats, fish and aged foods, broths, sauces and even wine.

The additive monosodium glutamate or MSG, also produces a strong umami taste. And then there are the foods that can amplify the umami taste when combined. Consider shellfish, dark mushrooms, salmon or mackerel.

Kantha is also working with a Canadian group teaching product developers and chefs the various aspects of umami and specifically maple syrup. She says pure maple syrup when combined with chicken for example can pack a powerful umami punch.

"Building in or enhancing the umami factor of food we can actually have a way to convince people stealthily to eat less of it," said Dr. Shelke. "Bulking up the senses is what it is all about."

There's newer research showing we may have a sixth taste sense for fat. Some people may be more sensitive to the fat taste making them less likely to over consume high fat foods. The Institute of Food Technologists, based in Chicago, has scientists around the world now studying and working with the chemical composition of foods, including umami.